Present harvester pick-ups for vegetables which may rest on the ground surface usually must cut below the surface of the ground to get all the crop. Sickle-bars operating below the ground surface have been widely used as have various types of sweep knives. However, when using any of such devices, soil is unavoidably taken into the harvester and must be shaken or sorted out. If the soil is moist it will not shake out but builds up on all the parts it contacts, soiling the crop and soon clogging the machine at various points. This is not as much of a problem in dry conditions in the irrigated far west, where the water can be shut off, as it is in the midwest.
Large forwardly-tilted steel disks with notched edges and overlapping to shear stems do a good job of gathering and lifting the crop onto the conveyor but the front edges must run under the soil surface in order to get all the crop. They also take in soil. Examples of such pick-ups are shown in U.S. Pat. Nos. 2,588,764; 2,606,416; 2,994,177; 3,796,268; and 3,921,723.
Those working in this field have, for some time, been trying to devise a harvester pick-up which will get the crop without taking in soil.